Combined telephone ringing and induction coil arrangement



Dec. 9, 1958 D. TlNl COMBINED TELEPHONE RINGING AND INDUCTION COIL ARRANGEMENT Filed Dee. 19, 1955 2 Sheets-Sheet 1 2 a 3 =1 Fi/ V FIG.I.'

35 Q O /O WI/ENTOR D. T IN I ATTORNEY Dec. 9, 1958 D. TlNl ,8

COMBINED TELEPHONE RINGING AND INDUCTION COIL ARRANGEMENT Filed Dec. 19, 1955 2 Sheets-Sheet 2 Z/@ 3/ a tj A TTOR/VE) COMBINED TELEPHQNE RINGING AND INDUC- TION CURL ARRANGEMENT Dante Tini, Milan, litaly, assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application December 19, 1955, Serial No. 561,706

Claims priority, applicationltaly December 24, 1954 13 Claims. (c1. 179 s1) This invention relates to telephone equipment and more particularly to improvements in subscriber sets incorporating induction and ringingcoils and utilizing polarized electromagnetic ringers.

Telephone designers have striven in the past to reduce the size of the components contained in telephone subset bases thereby achieving a reduction in Weight and cost of the equipment. Three important elements contained in the base of a telephone subset are the ringer, the induction coil and the capacitor. Important advances have recently been made in the manufacture of capacitors and equally important advances have been made in the development of high quality magnetic materials suitable for the use as cores of induction coils and magnetic circuits of the ringers resulting in considerable reduction in the physical size of those' 'componentsand yet maintaining efiicient performance. Despite the'advances, ithas been necessary to-separa'tely mount the ringer and 'induction coilsin the subsets and applicant has'now devised a new typeof telephone subset of a smaller size which is' achieved by the consolidation of the magnetic-core for the ringer with the magnetic core ofthe inducti'on coil each using a common magnetic path.

Accordingly'it is an object of the present invention to provide a new type of polarized ringer of "simple construc tion, of small size and having incorporated as apart of the magnetic core of the'ringer, the'magnetic core of the induction coil.

A feature of this" invention is the use of'a' magnetic sides of the induction coil' core and having two other 1 branches carrying the coils for the ringer.

A further feature of the invention for improving the mounting of some members of the ringer and lowering its costsof manufacture, consists 'in a device for clamping the permanent'magnet to the laminated core which'firrnly holds the magnetto thecore'inits right position and bears the shaft of the swingingarm'ature of the'ringermotor, firmly holds the two spoolscarrying' the electrical windings' and which are placed'on the two side arms of the magnetic core of the ringer without using supplementary clamping parts.-

Theabovomentionedam other features and objects'of this invention and-the manner of attaining them will'become more apparent and the invention itself will be best understood, by reference to the following description of an embodiment of the invention takenin conjunction with the accompanying drawings, wherein:

Fig. 1 is a front diagrammatic view of the rin ger in cluding the features of the'inventioni- Fig. 2 is aview in elevation of'the laminated'core 2,863,951 Patented Dec. 9, 19 58 Fig. 7 is a front view of a retaining plate which retains the armature pivot" pin shown in Figs. 1,3 and 6;

Referring now to Fig.-1,'th'er'e are shown some of the principal componentsof a telephone subset" box and which comprise a pair of bells 11, 11, a-hammer Scarried by ro'd 24 and coupled to armature 5. The armature is actuated by means of ringing coils 6, 7 in response to the alternating signalling current applied to coils 6, 7, 'as is well known by those skilledin telephony. There is also shown aninduction coil 25 which acts asa trans former to couple the telephone receiver (not shown) to theline (not shown). The Coils 6, 7 and coil 25 are mounted on a unitary core structure '1 which consists of laminations of a paramagnetic material having substantially a W shaped structure as'is more clearly seen in Fig. 2, consisting of a pair of vertical outer arms 2, 3 and a short central vertical arm 4; the coils 6 and 7 adapted to encircle arms 2 and 3, respectively. Thecentral arm 4 has a small bar-shaped permanent magnet 14" extending in prolongation thereof. The lower portion of l the core 1 consists of two oppo'sitely disposed L-shaped portions 12 and 13, separated by air gaps 15 and'15'. The winding of induction coil 25 is'adapted' to encircle the long arms of core'portion 13'. lt'will be seen that the axes of coils 6 and 7 are at-right angles'to the'axis-of'coil 25 so thatthere' is a minimum of inductive coupling thereamong.

Retur'ningto Fig. 1, the magnetic core '1 is fastened to two suitable brackets 9 and it} by means of fastening-devices 33, 34" which extend through-outer fasteningplates 35,55 into brackets 9 and 1%, respectively.- The core 1 is thus sandwiched between the brackets 9, 1t) andplates" 35, 35'. The bells 11,-11'

may be mounted in the box of the subset in any desired way ormay be mounted by means o'f suitable brackets (not shown) from core 1.

The magnet 14 has a cross-section similar'to that of central arin 4 and isprbvided'with a U-shaped slot 36 cut into its upper'su'rface.

In order to mount the magnet 14 atop the central arm 4, I provide a pair of opposed brackets 16 and 17 made of a suitable material which brackets are shown more particularly in Fig.4. The brackets Hand 17 comprise a rectangular straight portion 16; and 1711, respectively,

and an upper 3-sided portion16b' and 17b, respectively. The upper portions referred to are adapted to form the outline of a rectangle when placed in opposition to each other, the rectangle havingan inside dimension'corre in bracket 17 may be'threaded to receive'the' fasten'ing's 18, if desired. The brackets 16 and 17 in their'upp'er' portions '16b'and'17b', respectivelyare each provided with an aperture 30, 31 as shown in Fig. 4 and through which a pivot pin 21 is adapted to be inserted as shown clearly in Fig. 3. Brackets 16 and 17 are also provided with a pair of opposed outwardly extending lugs 26 and 27, the function of which will be later explained. The magnet 14 is provided with a transverse U-shaped slot 36 as shown in Fig. 2. The slot 36 is adapted to be aligned with the apertures 30 and 31 in brackets 16 and 17 and is adapted to accommodate the pivot pin 21 as shown in Fig. 3. Ringing sods and 7 are adapted to be placed over outer arms 2 and 3, respectively as shown in Fig. 1. The lug portions 26 and 27 are adapted to extend over the cheeks 2a and 3a of said windings, respectively, as shown clearly in Fig. 1 to prevent the windings from being moved upwardly.

Cooperating with the coils 6 and 7 there is provided a balanced armature and which comprises a straight portion 37 extending over the tops of the core arms 2 and 3 and having two downwardly extending studs 33, 38 made of diamagnetic material and which studs are adapted to cooperate with the upper surfaces of the arms 2 and 3 and prevent magnetic adherence thereto. The configuration of armature 5 is clearly shown in Fig. 5. The central portion of armature 5 is bent over downwardly on opposite sides thereof to form a U-shaped structure clearly shown in Fig. 3 and one of the arms of the U is extended perpendicularly outward at 22a to receive one end of rod 24 which extends perpendicularly therefrom and at the opposite end of which hammer 8 is attached. The U-shaped arms 22 of the armature 5 are provided with a pair of apertures 32 which are in register.

The induction coil 25 is mounted on the long leg of the L-shaped member 13 as shown clearly in Fig. 1 and it will be seen that the flux path of the induction coil includes the long arm 12 of the core 1 and that portions of the same arm 12 are included in the flux path of the coils 6 and 7, said portions being respectively betweeen arms 2 and 4 and arms 3 and 4. Air gaps and 15' prevent saturation of the magnetic material of the core 1. The assembly of the structure shown in Fig. l is relatively simple and includes the placement of the winding on the leg 13, the clamping of the core 1 to the brackets 9 and 10; the placement of coils 6 and 7 over the arms 2 and 3; the placement of the magnet 14 upon the arm 4 as shown in Fig. 2; the clamping of the magnet by means of the brackets 16 and 17; the placement of armature 5 in the position shown in Fig. 3; the placement of pivot pin 21 through the apertures 30, 32, 31 and 32', respectively. The lugs 27 and 26 extend over the cheeks 2a and 3a of coils 6 and 7, respectively, and retain them in position on the arms 2 and 3.

The configuration of pivot pin 21 is more clearly shown in Fig. 6 where it will be seen that the pin 21 includes a circumferential slot cut near one end of the pin and marked 21a. Pin 21 is inserted so that the slotted portion 21a extends outwardly from the left portion of the structure as shown in Fig. 3 so that the retaining plate 20 may retain it in position. The configuration of retaining plate 20 is clearly shown in Fig. 7. The retaining plate 20 consists of an off-set shaped piece of metal having portions 26a and 20b extending in parallel planes and joined by angular portion 20c. The upper portion 20a is provided with a key-hole slot 20d and the lower portion 20b is provided with a semi-circular slot 20a. The key hole slot 20d is provided to permit the insertion of member 20 over the left hand extending portion of pivot pin 21 until the plate 20 is in alignment with the slot 21a. The plate 20 is then drawn downwardly and the narrow portions of the slot 20d are adapted to prevent lateral movement of the pivot pin while permitting rotary movement thereof. The semi-circular aperture 20a is adapted to fit over bracket 16 and underneath fastening device 18. It will thus be seen that assembly of the device is simple and therefore economical. The structure of Fig. 1 may then be mounted to the base of a box (not shown) by means of the brackets 9 and 10 which support the entire ringing and inductive structure.

There is no problem of inductive losses sinve the induction coil 25 is not in operation when the windings 6 and 7 are energized and vice versa. The common flux path in the portion 12 as described above renders a sav ing in space and material as will be obvious to one skilled in the art.

While I have described above the principles of my invcntion in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims.

What is claimed is:

l. A telephone sub-set comprising signal receiving means and inductive coupling means for coupling said sub-set to a line, said signal receiving means comprising first ferromagnetic core means, said inductive coupling means comprising additional ferromagnetic core means, means interconnecting both said core means at a given angle to provide a common flux path for both said signal receiving means and said inductive coupling means while maintaining maximum inductive de-coupling therebetween.

2. A telephone subset as claimed in claim 1, wherein said interconnecting means comprises a magnetic core comprising a pair of spaced parallel outer arms, a central arm intermediate said outer arms, each of said arms mounted on a base portion extending normal to said arms, a fourth arm extending parallel to said base portion and a pair of interconnecting portions spacing said base portion from said fourth arm.

3. A telephone sub-set as claimed in claim 2 further comprising a permanent magnet attached to the end of said central arm in a manner whereby the total length of said central arm and said magnet is equal to the length of either of said outer arms.

4. A telephone subset as claimed in claim 2, wherein said signal receiving means comprises a pair of signalling coils, each coil extending over a different one of said outer arms, and said inductive coupling means comprises an induction coil extending over said fourth arm, whereby said outer arms and said fourth arm constitute magnetic cores for said signalling coils and said induction coil, respectively.

5. A telephone subset as claimed in claim 4, wherein said central arm further comprises a pair of brackets for mounting said magnet to said arm, each of said brackets having apertures for accommodating fastening devices for fastening to said arm, and a further aperture for accommodating a pivoting element.

6. A telephone subset as claimed in claim 5, wherein said permanent magnet is provided with a U-shaped slot in register with the further apertures in said brackets.

7. A telephone subset as claimed in claim 1, wherein said signal receiving means comprises a centrally balanced armature and a hammer extending in a direction normal to the length of said armature.

8. A telephone subset as claimed in claim 7, wherein said armature includes a U-shaped central portion having an aperture through each of its arms, said apertures in register.

9. A telephone subset as claimed in claim 8, further comprising a pivot element adapted to pass through the apertures in the central portion of said armature, the further apertures of said brackets and the U-shaped slot in said magnet.

10. A telephone subset as claimed in claim 9, wherein said pivot element comprises a circumferential slot adjacent an end thereof.

11. A telephone subset as claimed in claim 10, further comprising a retaining element for retaining said pivot element in a fixed axial position, said retaining element comprising an oif-set plate having a key hole slot there- 13. A telephone subset as claimed in claim 12, further in, the narrow portion of said slot adapted to slidably comprising a pair of core mounting brackets for mountfit wthin the circumferential slot in said pivot element, ing all of said arms as a unitary structure. said plate having a lower portion adapted to be clamped to one of said brackets and said central arm. 5 References (med in the file Of this Patent 12. A telephone subset as claimed in claim 5, where- UNITED STATES PATENTS in each of said brackets is provided with an opposite outwardly extending lug, said lugs adapted to extend 1,896,196 Green Feb. 7, 1933 over said signalling coils to retain said coils in position 2,502,273 Patry et a1 Mar. 28, 1950 on said outer arms. 10 2,643,300 De Stadelhofen et a1. June 23, 1953 

